Civil Engineering Reference
In-Depth Information
HEADER TIMBER SLOTTED ON TO FIXING POSTS
Internal lime plaster
Bales with compression
above the window
External
lime render
300mm x 75mm top timber
slotted into fixing posts
Linseed oil mastic
Durable timber dripmould
profile with dripgroove
up to 50mm x 50mm
25mm x 225mm
planed timber
225mm x 25mm
timber lining
Window
header. If this is the case, don't forget about
the compression gap for settlement.
run from the baseplate to the beam above.
These posts can be of various designs. A
timber frame style would use solid timber
and a compressive frame would use posts,
the design of which was compatible with
the method of lowering the frame once all
the bales were in position. The framing sill
is fixed after the straw below it has been
placed and compressed manually (see
'Fixing posts', on previous two pages).
Weather protection
The detailing around windows in particular
is very important, as the junction between
the window, sill and plaster can take a lot of
rain and so you need to be especially careful
to make sure this is done very well. Carol
Atkinson used the design shown overleaf,
which adds extra protection at this point,
for her windows (this is pictured on page
128). Details for ensuring good weather
protection around windows and doors are
included in Appendix 4.
With a framework, the dimensions of windows
and doors do not need to be multiples of
bale lengths, but the design should ensure
that the gap between one fixed post and the
next does relate to full or half-bale lengths,
to make the bale installation easier.
If there is a bale between the top of the
window and the beam above, framing must
be designed to carry the full width of the
bale, and for compressive frame methods
allowance should be made for settlement of
the top beam or wallplate on to the straw.
Framework methods
In framework methods, windows and doors
are designed into the framing, and usually
have upright posts either side of them that
